1. Field of the Invention
This invention relates generally to an apparatus to retrieve, store, and ship gas samples obtained from high pressure compressed gas sources for laboratory analysis, and specifically, to an automatic compressed breathing air sample retrieval kit that is used to retrieve, store, and ship breathing air samples obtained from stored compressed breathing air tanks that are maintained under high pressure, up to 6,000 psi, and that are typically used to charge scuba tanks and fire fighters' breathing tanks.
2. Description of the Prior Art
The use of compressed breathing air in scuba tanks for scuba diving is well known. Most scuba tanks maintain compressed breathing air at 3,000 psi for use when diving. Since the compressed air is directly utilized and provides the only source of air for the diver, the air source must be free of deleterious contaminants and must contain the proper mixture of nitrogen and oxygen to insure safe breathing for the diver. Compressed air bottles and tanks are also used by fire fighting personnel for a source of breathing air in smoke-filled areas. Therefore, it is imperative that the air be clean of contaminants and in the proper ratios of nitrogen and oxygen to insure safe, healthy breathing for fire fighters.
Scuba tanks and fire fighting air tanks are periodically refilled from sources of air stored in large, high pressure tanks pressurized up to 6,000 psi. The source of air is typically provided by commercial establishments for filling scuba and fire fighter tanks. In order to insure that the air is of proper quality, it is necessary for them to periodically analyze air samples obtained from these large, high pressure storage tanks. This is done by collecting the samples from each supply tank of high pressure compressed air and sending them to outside laboratories for testing. For accurate measurement of the air quality, it is critical to know the volume of air sampled to measure contamination levels based on contaminants found in the filters. It is essential that the sample testing be done correctly and accurately and that the retrieved samples be stored in containers or environments suitable for shipment to laboratory test sites. Moreover, it is commercially important for businesses that samples retrieved be kept simple and efficient to increase reliability and to decrease cost since frequent sampling of the breathing air source is required.
U.S. Pat. No. 3,372,274, issued to R. R. Landolt Mar. 5, 1968, shows a gas sampler that collects inert radioactive fission gas. A flow meter is shown to determine the amount of gas received into the system for proper analysis. U.S. Pat. No. 4,576,054, issued to H. S. Lalin Mar. 18, 1986, shows a dual mode gas sampler and pneumatic flow control system that allows simultaneous testing of gas samples for multiple test articles, either under constant pressure or constant flow. The system shown includes an air pump and a regulating diaphragm. U.S. Pat. No. 4,073,619, issued to Lawson Feb. 14, 1978, shows a device for sampling gas for analysis. Many of such prior art devices are complex in their structure and operation, and are not really suitable for daily commercial operations requiring numerous periodical sampling.
The present invention provides a sampling kit for compressed breathing air that is non-complex, inexpensive, automatic, and useful for collecting air samples from high pressure (up to 6,000 psi) compressed air supply tanks. The kit includes sampling adapters that can be used to connect to different supply sources, such as scuba tank supply sources or fire fighter supply sources. The pressure of the source itself is not critical. The kit is also conveniently mounted in a housing that allows a sample to be easily taken and readily shipped to a point for analysis. The kit itself can even be shipped through the mail to the laboratory for testing.
Accordingly, the present invention is a relatively non-complex sample retrieval device that is contained in a small-volume package in kit form that can be used for obtaining air samples from compressed breathing air storage tanks that have a great pressure range.